Effect of maleic anhydride grafting and the presence of oxidized wax on the thermal and mechanical behaviour of LDPE/silica nanocomposites

This paper reports on the introduction of sot-gel prepared nano-silica into low-density polyethylene (LDPE) and maleic anhydride grafted LDPE (LDPE-g-MA), as well as on the blending of these nanocomposites with different amounts of oxidized paraffin wax as a possible compatibiliser. LDPE/wax and LDPE-g-MA/oxidized wax blends were also investigated in comparison. The FTIR results indicated interactions between LDPE-g-MA, oxidized wax and nano-silica, and these interactions influenced the thermal and mechanical properties of the samples in a complex way. There are strong indications of a stronger interaction between the nano-silica and the oxidized wax, which caused the wax to preferably crystallize around the nano-silica. The melting and crystallization behaviour, thermal stabilities, tensile properties and theological behaviour, described in this paper, could be explained in terms of these observations. (c) 2009 Elsevier B.V. All rights reserved.